"This administration spent a large part of 2007 and 2008 campaigning to be this administration and saying that the way that the war had been prosecuted, the resources that hadn't been devoted to it, threatened our national security," White House press secretary Robert Gibbssaid. The documents cover the years 2004 to 2009; Obama shifted course in December 2009.

The posting of the documents Sunday night by the group WikiLeaks.org could complicate House approval of $37 billion in emergency war funding for Afghanistan and Iraq that has cleared the Senate, but it is expected to pass. Republicans, who have generally supported the war effort, were largely silent Monday about the WikiLeaks revelations, perhaps because the bulk of the documents concern the war effort during the George W. Bush administration.

Lawmakers said that the trove of documents may harden opposition but is unlikely to suddenly alter impressions of a war that the administration had previously acknowledged is a tough slog amid declining public support. The latest Washington Post-ABC News poll found 53 percent of adults say that the war has not been worth its costs, matching last month's highest-ever mark.

House Speaker Nancy Pelosi (D-Calif.), who is working to pass the bill that would help fund Obama's 30,000-troop boost for the war effort, said winning approval is "not an easy thing one way or another." Although the leaked documents may add to the volume of the debate, she said, they do not address current circumstances. "A lot of it predates the president's new policy," Pelosi said.

Rep. Mike Pence (R-Ind.), No. 3 in House leadership, said the revelations do not change his view of the conflict, nor does he expect a change in public sentiment. "Back home in Indiana, people still remember where the attacks on 9/11 came from," Pence said. "I don't believe this release will have a significant bearing on the sense of my constituents about the justness of this war or the imperative of its successful completion."

The diplomatic consequences of such an intelligence breach were harder to judge. In Islamabad, Pakistani officials reacted angrily to allegations in the documents that Pakistan's spy agency collaborated with the Taliban, with analysts warning the disclosure could have damaging consequences for Pakistan's relations with the United States. In Kabul, President Hamid Karzai was "shocked" that "such a huge number of documents were leaked" -- but not by the allegations contained in them, his spokesman told reporters.

State Department spokesman P.J. Crowley said that the U.S. ambassadors in Kabul and Islamabad, Pakistan, as well as Adm. Mike Mullen, the chairman of the Joint Chiefs of Staff, had warned senior officials there about the pending WikiLeaks disclosure and said it had not been sanctioned by the U.S. government. "We wanted to make sure they understood the context under which these documents would be released . . . that this represents a crime and that we are investigating it," he said.

Gibbs, at his daily briefing, argued that the Obama administration had largely identified the problems detailed in the documents and had taken steps to address them. "We have certainly known about safe havens in Pakistan. We have been concerned about civilian casualties for quite some time," he said. "And on both of those aspects, we've taken steps to make improvements." As for relations with Pakistan, "we understand that the status quo is not acceptable and that we have to continue moving this relationship in the right direction."

Gibbs's case was echoed at the State Department and in statements issued by leading lawmakers.

"Most of these documents are several years old and may well reflect situations and conditions and circumstances that have either been corrected already or are in the process of being corrected," Crowley said. "Some of the documents talked about a conflict that was underresourced and that was a fundamental element of the strategy review overseen by the president."

Sen. Joseph I. Lieberman (I-Conn.) said the documents "add nothing to the public understanding of the war in Afghanistan. The materials -- which cover the period from 2004 to 2009 -- reflect the reality, recognized by everyone, that the insurgency was gaining momentum during these years while our coalition was losing ground."

"Most of it is old news," said Sen. John McCain (R-Ariz.), the president's opponent in the 2008 election. "The emerging picture from this leak adds up to little more than what we knew already -- that the war in Afghanistan was deteriorating over the past several years and that we were not winning."

But Sen. John F. Kerry (D-Mass.), the chairman of the Senate Foreign Relations Committee and normally a reliable defender of the administration's policies, warned the documents "raise serious questions about the reality of America's policy toward Pakistan and Afghanistan" and "may very well underscore the stakes and make the calibrations needed to get the policy right more urgent."

From a public relations standpoint, the documents could hardly have appeared at a worse time for the Obama administration. The previous House vote this month revealed how skeptical Democrats have grown about the war effort. Although it passed narrowly -- 215 to 210 -- the majority of Democrats had voted for an amendment that would require Obama to present a plan by April for the "safe, orderly and expeditious redeployment of U.S. troops." That amendment also would have allowed a vote in Congress to stop additional war funding if withdrawal does not start by next July, the time administration officials have said they will start reducing forces in Afghanistan.

Jim Manley, spokesman for Senate Majority Leader Harry M. Reid (D-Nev.), said: "There's growing questions being raised on the Hill. All you have to do is look at the votes on the supplemental" funding bill.

The obvious comparison that many seemed to jump on initially was the Pentagon Papers, which helped galvanize public doubts about the Vietnam War. But unlike the Pentagon Papers, these documents -- although they are closer to a real-time assessment and although they land in the superheated Internet era -- do not reveal any strategy on the part of the government to mislead the public about the mission and its chances for success.

Gibbs condemned the leak of the documents, calling their publication "a concerning development in operational security" that "poses a very real and potential threat to those that are working hard every day to keep us safe." But he went out of his way to praise the New York Times -- one of three news organizations given an initial peek by WikiLeaks -- for its responsible handling of the documents once it had received them.

Col. Dave Lapan, a Pentagon spokesman said officials are conducting a review of the documents "to try to determine the potential damage to lives of our service members and our coalition partners, whether they reveal sources and methods and any potential damage to national security." The probe, he told reporters Monday, will take "days, if not weeks."